A CT Scan has a higher resolution than MRI, or X-ray. Though a CT has some radiation because it's still using X-radiation, it's less than what's used for an X-ray. Supposedly, they are coming out with a "Color" version of a CT Scan real soon. However, another new technology is Ultrasound, which can have an even higher resolution, but it's still in the making.
When I went through my first bleed, they also gave me medication that was to stop the bleeding, allowing the tissues in the lungs to heal a little...It seems with every bleed you have, your lungs haven't had the chance to heal from the first bleed.
Definitely take Diane's advice and get a CT Scan and find the source of the problem of the bleeding to stop it.